It is known that a red streak remains on the skin after irritating it with an object such as a fingernail, spoon handle, or laboratory spatula. The degree of redness or persistence duration is used as a basis for skin sensitivity. This rough method has the disadvantage, however, of yielding different results since the local pressure of the mechanical action varies considerably, depending on the investigator, the pressure applied and the object used.
A fine gradation of the degree of skin sensitivity or a reproducible standardized determination of the readiness of the skin to react to mechanical stimulation has not as yet been possible. This property of the skin is of particular importance, especially for skin property valuation, and thus a method to provide a standardized pressure to the skin must be found.
In dermatology and cosmetics, it is desirable to have a simple means for evaluating skin sensitivity. The purpose of this invention is to create such a device. This is accomplished according to the invention, by the fact that at least one pressure element projecting from a base is provided. This element is compressible into the base of the device, against the action of an elastic system or a spring element with a known spring force. The outer end of the pressure element is provided with an rough surface whose area is directly proportional to the spring tension and whose roughness is inversely proportional to the spring tension.
By this means, very accurate determinations of skin sensitivity can be made since the skin is always subjected to exactly the same definite pressure. Further features and advantages of the invention will be evident from the following description and from the claims.